Aaron Ramsey was sent off and Alex Oxlade-Chamberlain saw a late drive hit the post in what was a frantic match in Istanbul but Arsenal will go into the return leg at the Emirates Stadium the happier side.

It was almost a horror start for Arsenal as Demba Ba's shot straight from kick-off clattered the top of the crossbar as goalkeeper Wojciech Szczesny got a hand to it. Ba proved a constant threat all night for Besiktas and stung the hands of Szczesny again with a rasping volley, before Olivier Giroud went close with a deflected looped effort.

Good work from Alexis Sanchez saw Santi Cazorla go close, before Szczesny had to be sharp to deny Veli Kavlak on the half hour mark. Jack Wilshere kept Tolga Zengin busy at the other end with a curling effort.

Ba wasted a great chance on the stroke of half-time; following a rare mistake from the otherwise impressive Calum Chambers, the Besiktas forward cut inside Laurent Koscielny only to drag his shot wide of the post.

The home side continued to exert the pressure early in the second half. Olcay Sahan broke down the left but could only curl the ball around the wrong side of the post with Szczesny rooted to the spot.

Mikel Arteta will be a doubt for the second leg after he departed with what appeared to be an ankle injury. However, Ramsey will definitely miss out after the midfielder naively grabbed the shirt of Oguzhan Ozyakup while already on a yellow card. Referee Milorad Mazic wasted no time in showing Ramsey his first red card of his club career.

Substitute Oxlade-Chamberlain almost won the game late on for Wenger, but his late drive was pushed onto the post by Zengin. Besiktas coach Slaven Bilic was then sent to the stands with only seconds remaining.

Athletic Bilbao will have the upper hand back at San Mames after holding Napoli to a 1-1 draw.

The Primera Division and Serie A giants were pitted against each other in a battle to reach the group stages and Athletic took the initiative with Iker Muniain scoring four minutes before the break in Naples.

Napoli hit back after the interval as former Real Madrid striker Gonzalo Higuain fired a leveller on 68 minutes but the Basque outfit will fancy their chances of winning the second leg and progressing to the next stage.

There were five goals in the first half of action in the Danish capital as Bayer Leverkusen claimed a 3-2 win at FC Copenhagen.